Fans living in Frankfurt were banned from the last-16 second leg after trouble at the first game in Germany, but hundreds travelled to Italy anyway.

"It's not possible to still see this in 2023," said Napoli defender Juan Jesus.

"It's bad for the city and bad for soccer. People come, then destroy, then leave, it's not a good thing - we are sorry to see these scenes."

Six police officers were injured during the skirmishes, according to Alessandro Giuliano, who is responsible for public safety in Naples.

The force is attempting to identify 470 German fans who stayed in the city, and were scouring images to establish those responsible for the disorder, he told a press conference.

The first clashes occurred on Wednesday afternoon in Naples and continued after the match, an easy 3-0 win for Napoli which took them through to the Champions League quarter-finals for the first time.

Smoke bombs and flares, chairs, bottles and metal poles were thrown at police, who responded with tear gas.

Later, Napoli fans were filmed by Italian media throwing objects at buses carrying Eintracht fans and Naples mayor Gaetano Manfredi condemned the "unacceptable" violence.

Eintracht board member Philipp Reschke echoed that view and said: "We deeply regret the events that have taken place. There is absolutely nothing to justify this violence, it is unacceptable.

"It harms football, it harms Eintracht Frankfurt and it harms our efforts to stick up for fans who want to watch a game without restrictions in the stadium."

Nine people were arrested after trouble also flared during the first meeting between the sides in February.